Canadian Manufacturer of Anti-Abuse OxyContin Bioequivalent Seeks FDA Approval

Toronto, ONConcern over the growing opioid epidemic has prompted forward-thinking drug manufacturers and pharmaceuticals to consider anti-tampering and abuse deterrents in the design of new drugs. The US Food and Drug Administration (FDA) however, which has recently vowed to fight opioid abuse, has found it necessary to question the claims of a Canadian manufacturer that potential abuse of its OxyContin bioequivalent could be effectively deterred.

Intellipharmaceutics International Inc. (Intellipharmaceutics) has applied to market Rexista in the US. While the FDA did not require efficacy studies for Rexista given that it’s a bioequivalent to OxyContin and thus would present similar adverse reactions to known OxyContin side effects, the federal regulator nonetheless has Rexista in its sights over the manufacturer’s claims of anti-abuse features built into the design of the drug.

Data from pharmacokinetic studies submitted by the manufacturer to support its application and claims of anti-abuse possessed limited value, staff with the FDA said, given that the data was generally collected from single-dose studies on healthy volunteers taking naltrexone – the latter a prescription drug that blocks the effects of addictive opioid medications.

Rexista, according to the Canadian manufacturer, contains a blue dye that is released when tampering with the drug occurs, although the exact nature of what that tampering might be was not made clear. Intellipharmaceutics did suggest that the release of the blue dye upon tampering “causes stigmatization to the potential abuser.”

Intellipharmaceutics also submitted in its brief to the FDA that Rexista contains an irritant designed to deter abuse from snorting – the latter possible when the tablets are ground into powder. While the FDA noted that crush resistance was not a property submitted as an abuse deterrent, it was nonetheless noted that Rexista is easier to crush into a fine dust than OxyContin, its bioequivalent.

The Rexista application was to have been put before an FDA advisory committee this month, in order to weigh the manufacturer’s claims of abuse-deterrence against the potential for Big Pharma deceptive marketing were claims made by the manufacturer to be unsupported by data. The FDA has said that no abuse liability studies were submitted with the Rexista application.

Opioid medications are prescribed to treat chronic pain for which less-robust painkillers are ineffective. To be successful – and to reduce risk of side effects inherent to addictive opioid medications – candidates for opioids are carefully conditioned, and transitioned to opioids. Abuse of opioids, however, runs the risk of the full impact of an opioid on an individual without benefit of prior conditioning to them.

It has been noted that abuse of addictive opioid medications and heroin are linked to some 30,000 fatal overdoses each year in the US. The FDA, through agency Commissioner Scott Gottlieb, has vowed to fight the opioid epidemic through whatever power the FDA has in its possession.

One of those more recent thrusts is an increased focus on opioids that feature abuse deterrent properties. Earlier this month a number of pharmaceuticals lobbied the FDA to phase out opioids without abuse deterrents once a sufficient number of opioids that carry abuse-deterrent properties have been approved, and made available.

Still, the FDA remains concerned that opioids that feature deterrents against abuse are not marketed as less-addictive as opioids that lack abuse-deterrence. The FDA, for its part, has signaled its intent to study how manufacturers, marketers, and health providers perceive and prescribe the anti-deterrent opioids, and whether new language is needed on product labels and official prescribing information in an effort to ensure a clear understanding of the risks and benefits.

The goal would be to help mitigate the opioid epidemic, rather than heighten it.

The FDA, in requiring a closer look at Rexista, is not suggesting Intellipharmaceutics is in any way suspected of any potential for misleading labelling. The scrutiny is over whether, or not the abuse-deterrence properties of Rexista, as claimed and outlined in the application, are adequately supported by data.

Intellipharmaceutics International Inc. was founded as Intellipharmaceutics Ltd. in 1998 and is based in Toronto.